Side effects of naproxen and aspirin can include stomach upset and nausea.
Naproxen and aspirin are widely available medications used to manage mild to moderate pain. Individuals sometimes combine these medications in an effort to receive more pain relief. Mixing these drugs occasionally may not be harmful, but there are distinct interactions between the two that can make high-dose or high-frequency combinations decidedly unsafe.
Side effects of aspirin and naproxen can include fever.
Both drugs have distinct, though overlapping, ways of affecting the human body, which contributes to their level of safety when combined. Naproxen and aspirin inhibit the enzyme cyclooxygenase-2 (COX-1) involved in the inflammatory reaction of the immune system. By doing so, they reduce pain and swelling. They also inhibit a type of COX enzyme in the stomach, COX-1, which is involved in protecting stomach tissue from gastric acid, however, leading to a risk of stomach damage when either one is given alone.
Bloody urine can be a side effect of naproxen and aspirin.
Research has shown that taking naproxen with aspirin greatly increases the chance of stomach damage. This risk is greater than taking higher doses of either drug alone. Users of both drugs simultaneously, at therapeutic doses, were twice as likely to have problems such as stomach perforation, stomach bleeding and ulcers. These drugs taken together can be considered unsafe, even at relatively low dosages.
Aspirin is sometimes given for the protective effect it can have on the heart, based on its ability to prevent blood cells in the bloodstream from clotting. Studies have shown that this effect, caused by aspirin’s inhibition of COX-1, is avoided when naproxen and aspirin are taken two hours apart. People who take aspirin to prevent heart attacks may not receive this beneficial effect if both drugs are taken in a short period of time.
Taking naproxen and aspirin together can cause stomach damage.
The similarities of naproxen and aspirin in their mechanisms of action mean that they also have similar side effects. Potential side effects can increase in severity and frequency when taken at the same time. Less serious side effects that can result from this combination can include nausea, heartburn, and upset stomach.
Medical assistance should be sought immediately if more serious side effects appear after taking one or both of these medications. Blood in the urine or stool, stomach pain, or persistent fever are effects that can result from these medications. They can be indicative of serious medical conditions, such as stomach bleeding. As determined by the studies mentioned above, these effects are more likely to occur if the two drugs are taken together.